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Seasonal variation and partitioning of endocrine disrupting chemicals in waters and sediments of the Pearl River system, South China 全文
2016
Gong, Jian | Duan, Dandan | Yang, Yu | Ran, Yong | Chen, Diyun
Endocrine disrupting chemicals (EDCs) were seasonally investigated in surface water, suspended particulate matter, and sediments of the Pearl River Delta (PRD), South China. EDC concentrations in the surface water were generally higher in the summer than in winter. The surface water in the investigated rivers was heavily contaminated by the phenolic xenoestrogens. Moreover, the in-situ log Ksoc and log Kpoc values and their regression with log Kow in the field experiments suggest that binding mechanisms other than hydrophobic interaction are present for the sedimentary organic carbon and particulate organic carbon (SOC/POC). The logKsoc–logKow and logKpoc–logKow regression analyses imply that higher complexity of nonhydrophobic interactions with EDCs is present on the SOC samples comparing with the POC samples, which is related to their different sources.
显示更多 [+] 显示较少 [-]Natural and anthropogenic radioactivity in the environment of Kopaonik mountain, Serbia 全文
2016
Mitrović, Branislava | Ajtić, Jelena | Lazić, Marko | Andrić, Velibor | Krstič, Nikola | Vranješ, Borjana | Vićentijević, Mihajlo
To evaluate the state of the environment in Kopaonik, a mountain in Serbia, the activity concentrations of 4 K, 226Ra, 232Th and 137Cs in five different types of environmental samples are determined by gamma ray spectrometry, and radiological hazard due to terrestrial radionuclides is calculated. The mean activity concentrations of natural radionuclides in the soil are higher than the global average. However, with an exception of two sampling locations, the external radiation hazard index is below one, implying an insignificant radiation hazard. Apart from 40K, content of the natural radionuclides is predominantly below minimum detectable activities in grass and cow milk, but not in mosses. Although 137Cs is present in the soil, grass, mosses and herbal plants, its specific activity in cow milk is below minimum detectable activity. Amongst the investigated herbal plants, Vaccinium myrtillus L. shows accumulating properties, as a high content of 137Cs is detected therein. Therefore, moderation is advised in consuming Vaccinium myrtillus L. tea.
显示更多 [+] 显示较少 [-]Evidence for differential effects of reduced and oxidised nitrogen deposition on vegetation independent of nitrogen load 全文
2016
van den Berg, Leon J.L. | Jones, Laurence | Sheppard, Lucy J. | Smart, S. M. (Simon M.) | Bobbink, Roland | Dise, Nancy B. | Ashmore, M. R. (Mike R.)
Nitrogen (N) deposition impacts natural and semi-natural ecosystems globally. The responses of vegetation to N deposition may, however, differ strongly between habitats and may be mediated by the form of N. Although much attention has been focused on the impact of total N deposition, the effects of reduced and oxidised N, independent of the total N deposition, have received less attention. In this paper, we present new analyses of national monitoring data in the UK to provide an extensive evaluation of whether there are differences in the effects of reduced and oxidised N deposition across eight habitat types (acid, calcareous and mesotrophic grasslands, upland and lowland heaths, bogs and mires, base-rich mires, woodlands). We analysed data from 6860 plots in the British Countryside Survey 2007 for effects of total N deposition and N form on species richness, Ellenberg N values and grass:forb ratio. Our results provide clear evidence that N deposition affects species richness in all habitats except base-rich mires, after factoring out correlated explanatory variables (climate and sulphur deposition). In addition, the form of N in deposition appears important for the biodiversity of grasslands and woodlands but not mires and heaths. Ellenberg N increased more in relation to NHx deposition than NOy deposition in all but one habitat type. Relationships between species richness and N form were habitat-specific: acid and mesotrophic grasslands appear more sensitive to NHx deposition while calcareous grasslands and woodlands appeared more responsive to NOy deposition. These relationships are likely driven by the preferences of the component plant species for oxidised or reduced forms of N, rather than by soil acidification.
显示更多 [+] 显示较少 [-]Light pollution reduces activity, food consumption and growth rates in a sandy beach invertebrate 全文
2016
Luarte, T. | Bonta, C.C. | Silva-Rodriguez, E.A. | Quijón, P.A. | Miranda, C. | Farias, A.A. | Duarte, C.
The continued growth of human activity and infrastructure has translated into a widespread increase in light pollution. Natural daylight and moonlight cycles play a fundamental role for many organisms and ecological processes, so an increase in light pollution may have profound effects on communities and ecosystem services. Studies assessing ecological light pollution (ELP) effects on sandy beach organisms have lagged behind the study of other sources of disturbance. Hence, we assessed the influence of this stressor on locomotor activity, foraging behavior, absorption efficiency and growth rate of adults of the talitrid amphipod Orchestoidea tuberculata. In the field, an artificial light system was assembled to assess the local influence of artificial light conditions on the amphipod's locomotor activity and use of food patches in comparison to natural (ambient) conditions. Meanwhile in the laboratory, two experimental chambers were set to assess amphipod locomotor activity, consumption rates, absorption efficiency and growth under artificial light in comparison to natural light-dark cycles. Our results indicate that artificial light have significantly adverse effects on the activity patterns and foraging behavior of the amphipods, resulting on reduced consumption and growth rates. Given the steady increase in artificial light pollution here and elsewhere, sandy beach communities could be negatively affected, with unexpected consequences for the whole ecosystem.
显示更多 [+] 显示较少 [-]Measurement of human CYP1A2 induction by inhalation exposure to benzo(a)pyrene based on in vivo isotope breath method 全文
2016
Duan, Xiaoli | Shen, Guofeng | Yang, Hongbiao | Lambert, George | Wei, Fusheng | Zhang, Junfeng (Jim)
Cytochrome P450 1A2 (CYP1A2) is an enzyme involved in the metabolic activation of certain carcinogens, and inducible by toxic substrates. To date, few studies have investigated in vivo CYP1A2 induction in humans and its relationship to polycylic aromatic hydrocarbons (PAHs) like benzo(a)pyrene (BaP). Non-smoking healthy male coke-oven workers (n = 30) were recruited as ‘exposure’ group, and non-smoking healthy office workers in the same city (n = 10) were selected as ‘control’ group, to test whether high inhalation exposure to PAHs can induce CYP1A2 activity in human livers. Significantly higher inhalation exposure of PAHs were found among the exposure group compared to the control. Inhalation BaP exposure concentration in the exposure group was more than 30 times higher than the control group (p < 0.001). However, the exposure group did not exhale significant higher levels of ¹³CO2/¹²CO2 in breath samples (p = 0.81), and no significant relationship was found between the inhaled BaP concentration and the ¹³CO2/¹²CO2 ratio (p = 0.91). A significant association was found between the ¹³CO2/¹²CO2 exhalation and dietary BaP intake level. Hepatic CYP1A2 activity/induction level was not effected by inhaled BaP but was altered by ingestion of BaP.
显示更多 [+] 显示较少 [-]Enhanced anaerobic dechlorination of polychlorinated biphenyl in sediments by bioanode stimulation 全文
2016
Yu, Hui | Feng, Chunhua | Liu, Xiaoping | Yi, Xiaoyun | Ren, Yuan | Wei, Chaohai
The application of a low-voltage electric field as an electron donor or acceptor to promote the bioremediation of chlorinated organic compounds represents a promising technology meeting the demand of developing an efficient and cost-effective strategy for in situ treatment of PCB-contaminated sediments. Here, we reported that bioanode stimulation with an anodic potential markedly enhanced dechlorination of 2,3,4,5-tetrachlorobiphenyl (PCB 61) contained in the sediment at an electronic waste recycling site of Qingyuan, Guangdong, China. The 110-day incubation of the bioanode with a potential poised at 0.2 V relative to saturated calomel electrode enabled 58% transformation of the total PCB 61 at the initial concentration of 100 μmol kg⁻¹, while only 23% was reduced in the open-circuit reference experiment. The introduction of acetate to the bioelectrochemical reactor (BER) further improved PCB 61 transformation to 82%. Analysis of the bacterial composition showed significant community shifts in response to variations in treatment. At phylum level, the bioanode stimulation resulted in substantially increased abundance of Actinobacteria, Bacteroidetes, and Chloroflexi either capable of PCB dechlorination, or detected in the PCB-contaminated environment. At genus level, the BER contained two types of microorganisms: electrochemically active bacteria (EAB) represented by Geobacter, Ignavibacterium, and Dysgonomonas, and dechlorinating bacteria including Hydrogenophaga, Alcanivorax, Sedimentibacter, Dehalogenimonas, Comamonas and Vibrio. These results suggest that the presence of EAB can promote the population of dechlorinating bacteria which are responsible for PCB 61 transformation.
显示更多 [+] 显示较少 [-]Distributions and compositions of old and emerging flame retardants in the rhizosphere and non-rhizosphere soil in an e-waste contaminated area of South China 全文
2016
Wang, Shaorui | Wang, Yan | Song, Mengke | Luo, Chunling | Li, Jun | Zhang, Gan
We investigated rhizosphere effects on the distributions and compositions of polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and dechlorane plus (DPs) in rhizosphere soils (RS) and non-rhizosphere soils (NRS) in an e-waste recycling area in South China. The concentrations of PBDEs, NBFRs, and DPs ranged from 13.9 to 351, 11.6 to 70.8, and 0.64 to 8.74 ng g⁻¹ in RS and 7.56 to 127, 8.98 to 144, and 0.38 to 8.45 ng g⁻¹ in NRS, respectively. BDE-209 and DBDPE were the dominant congeners of PBDEs and NBFRs, respectively. PBDEs, NBFRs, and DPs were more enriched in RS than NRS in most vegetables species. Further analysis suggested that the differentiation of the rhizosphere effect on halogenated flame retardants (HFRs) was not solely controlled by the octanol-water coefficients. This difference was also reflected by the correlations between total organic carbon (TOC) and PBDEs, NBFRs, or DPs, which indicated that organic carbon was a more pivotal controlling factor for PBDEs and DPs than for NBFRs in soil. We also found significant positive correlations between PBDEs and their replacement products, which indicated a similar emission pattern and environmental behaviour.
显示更多 [+] 显示较少 [-]A global perspective on the use, occurrence, fate and effects of anti-diabetic drug metformin in natural and engineered ecosystems 全文
2016
Briones, Rowena M. | Sarmah, Ajit K. | Padhye, Lokesh P.
Metformin is the most commonly used anti-diabetic drug in the world. When consumed, this unmetabolised pharmaceutical compound is excreted by the body and eventually enters the environment through a variety of pathways. Based on its high consumption and excretion rates, high concentrations of metformin have been detected in influents of wastewater treatment plants. Metformin and its transformation product, guanylurea, are also expected to be present in other aquatic environments based on their physico-chemical properties. Not surprisingly, guanylurea has also been detected in surface water, groundwater, and drinking water. Available information on ecotoxicological effects of metformin suggests that metformin is a potential endocrine disruptor and thus further emphasising the threat this drug could pose to our environment. This review provides a comprehensive overview of metformin and critically discusses available literature data with respect to its global use/demand, occurrence, fate and ecotoxicity in treatment facilities equipped with conventional and advanced treatment technologies, and its degradation/removal mechanisms. Final section highlights the existing knowledge gaps regarding its ultimate fate under the natural and engineered ecosystems and identifies some important research areas requiring urgent attention from regulatory makers and scientific community.
显示更多 [+] 显示较少 [-]Association of urinary metals levels with type 2 diabetes risk in coke oven workers 全文
2016
Liu, Bing | Feng, Wei | Wang, Jing | Li, Yaru | Han, Xu | Hu, Hua | Kwok, Woon | Zhang, Xiaomin | He, Meian
Studies indicated that occupationally exposed to metals could result in oxidative damage and inflammation and increase cardiovascular diseases risk. However, epidemiological studies about the associations of metals exposure with diabetes risk among coke oven workers were limited.This study aims to investigate the potential associations of 23 metals levels with the risk of diabetes among coke oven workers.The analysis was conducted in a cross-sectional study including 1493 participants. Urinary metals and urinary polycyclic aromatic hydrocarbons (PAHs) metabolites levels were determined by inductively coupled plasma mass spectrometer and gas chromatograph-mass spectrometer respectively. Multivariate logistic regression was used to investigate the associations of urinary metal levels with diabetes risk with adjustment for potential confounding factors including gender, age, BMI, education, smoking, drinking, physical activity, hypertension, hyperlipidemia and urinary PAHs metabolites levels.Compared with the normoglycemia group, the levels of urinary copper, zinc, arsenic, selenium, molybdenum, and cadmium were significantly higher in the diabetes group (all p < 0.05). Participants with the highest tertile of urinary copper and zinc had 2.12 (95%CI: 1.12–4.01) and 5.43 (95%CI: 2.61–11.30) fold risk of diabetes. Similar results were found for hyperglycemia risk. Besides, participants with the highest tertile of manganese, barium, and lead had 1.65(1.22–2.23), 1.60(1.19–2.16) and 1.45(1.05–1.99) fold risk of hyperglycemia when compared with the lowest tertlie.The results indicated that the urinary copper and zinc levels were positively associated with the risk of diabetes and hyperglycemia among coke oven workers. Urinary manganese, barium and lead levels were also associated with increased risk of hyperglycemia independently of other traditional risk factors. These findings need further validation in prospective study with larger sample size.
显示更多 [+] 显示较少 [-]Microplastics in sediments of the Changjiang Estuary, China 全文
2016
Peng, Guyu | Zhu, Bangshang | Yang, Dongqi | Su, Lei | Shi, Huahong | Li, Daoji
Microplastics are plastics that measure less than 5 mm in diameter. They enter the marine environment as primary sources directly from industrial uses, as well as secondary sources resulting from the degradation of large plastic debris. To improve the knowledge of microplastic pollution in China, we investigated samples from 53 estuarine sediment locations collected with a box corer within the Changjiang Estuary. Microplastics (<5 mm) were extracted from sediments by density separation, after which they were observed under a microscope and categorized according to shape, color and size. Identification was carried out using Micro-Fourier-Transform Infrared Spectroscopy (μ-FT-IR).The abundance of microplastics in the Changjiang Estuary was mapped. The mean concentration was 121 ± 9 items per kg of dry weight, varying from 20 to 340 items per kg of dry weight. It was found that the concentration of microplastics was the highest on the southeast coast of Shanghai. The distribution pattern of microplastics may be affected by the Changjiang diluted water in summer. All of the microplastics collected were categorized according to shape, color and size. Among which fiber (93%), transparent (42%) and small microplastics (<1 mm) (58%) were the most abundant types. No clear correlation between microplastics and the finer sediment fraction was found. Rayon, polyester, and acrylic were the most abundant types of microplastics identified, indicating that the main source of microplastics in the Changjiang Estuary was from washing clothes (the primary source). It is possible to compare microplastic abundance in this study with the results of other related studies using the same quantification method. The identification of microplastics raises the awareness of microplastic pollution from drainage systems. The prevalence of microplastic pollution calls for monitoring microplastics at a national scale on a regular basis.
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